"There's been an inordinate amount of media attention on one threat group, and that has required additional security measures," Morgan said. The corrections department also was preparing for a Monday memorial service for Clements, she said.

The 211 gang is one of the most vicious white supremacist groups operating in the nation's prisons, comparable to the Aryan Brotherhood of Texas, according to the Southern Poverty Law Center, which tracks extremist groups.

Founded in 1995 to protect white prisoners from attacks, it operates only in Colorado and has anywhere from between a couple hundred to 1,000 members, senior fellow Mark Potok said Friday.

Legal records show Ebel was convicted of several crimes in Colorado dating back to 2003.

Scott Robinson, a criminal defense attorney and media legal analyst, represented Ebel in 2003 and 2004. He said Ebel had been sentenced to a halfway house for a robbery charge in 2003 before he was accused in two additional robbery cases the following year that garnered prison sentences of three and eight years.